Insulated tow-piece terminal



March 31, 1970 v.1. IANTORNO ET AL INSULATED TWO-PIECE TERMINAL Filed Oct. 29, 1968 JAMES BY JOHN WAGNER JOHN P. CHANDLER HIS ATTORNEY.

United States Patent ()flice 3,504,107 Patented Mar. 31, 1970 3,504,107 INSULATED TWO-PIECE TERMINAL James Iantorno, Mamaroneck, and John Wagner, Pleasantville, N.Y., assignors to Sealectro Corporation, Mamaroneck, N.Y., a corporation of New York Filed Oct. 29, 1968, Ser. No. 771,433 Int. Cl. H01b 17/26 US. Cl. 174-153 4 Claims ABSTRACT OF THE DISCLOSURE A two piece terminal, and method of installing it, to be secured in a hole within a panel and comprising a resilient bushing insulator with a flange at its upper end, a conductive pin positioned within the bushing and having a shank and an enlarged non-smooth section above the shank,'and a barb-like annular flange between the ends of the shank so that when the assembly is placed in said hole, and the lower end of the insulator is supported against substantial movement, and the nonsmooth section is driven into the area of the bushing enclosed by the panel, the portion of the bushing lying below the panel will increase in diameter.

This invention relates to an insulated terminal designed to reduce costs in manufacturing and installing, and relates more particularly to a novel two-piece insulated terminal comprising an insulating bushing which passes freely into a hole in a chassis, panel or the like, and having a head which limits downward travel into the hole. A conductive pin is positioned part way into a bore in the bushing when it leaves the manufacturer. An enlarged knurled section is formed below a wire-attaching upper end. A tapered section below the knurled section leads to an elongated shank and between the ends of the shank there is an enlarged barb-like annular flange. After the assembly is in place in the hole, the pin is driven home in the bushing, causing the enlarged knurled section to enter the area of the bushing enclosed by the panel. This has two results: one, it firmly secures the bushing in the panel opening; and two, it moves some of the deformable bushing material out below the opening, increasing its diameter and forming a shoulder.

The parts of the conductive pin are so proportioned that when the knurled section is in the latter position, the enlarged barb-like flange is adjacent the lower end of the bushing. Driving this flange into the bushing would tend to elongate the bushing except that its lower end is supported against substantial movement at least during part of the downward travel and causes the bushing to assume a bulbous or spherical configuration with the shoulder, just mentioned, engaging the panel.

In the drawing:

FIG. 1 is a side elevation, partially in section, of an insulated feed-through terminal of the present invention and the tools used in its installation;

FIG. 2 shows the terminal in partly installed condition;

FIG. 3 shows the completed assembly;

FIG. 4 is similar to FIG. 1 but illustrates a different tool set-up;

FIG. 5 shows the terminal partly installed;

FIG. 6 shows the completed assembly.

The two piece terminal assembly for mounting in secured relation in a hole 8 in a panel, chassis, or the like 9, is shown in FIG. 1 in partially assembled condition, i.e., the condition of assembly when it leaves the manufacturer.

The assembly includes a conductive pin 10 and a bushing 11 of deformable dielectric material such as Teflon, and having a central through bore 12 and a flange 14 at its upper end limiting downward travel of the bushing in the chassis. A bevel 15 is formed at its upper and lower ends. The conductive pin 10 has a lower shank 16, preferably of larger diameter than the bore 12, and whose length is only slightly less than the height of the bushing so that in the condition when first manufactured, its lower end extends almost to the lower end of the bushing. Between its ends the shank has an annular flange 18 whose edge may be sharp or barb-like. Its shape in cross section should preferably be frusto-conical with a horizontal upper annular ledge 19. Extending upwardly from the upper end of the shank is an enlarged non-smooth section 20 preferably of knurled contour, and between the two sections is a short outwardly tapered or conical section 21. Above the knurled section is a short section 25 of uniform diameter but of lesser diameter than that of knurled section 20. At the upper end of the pin is a wire wrap section 24 here shown as being bifurcated to facilitate soldering and there is a shoulder 23 at the lower end of the wire wrap section.

The bushing 11 is preferably formed of polytetrafluoroethylene or other material having similar properties and has such a diameter as to move freely into the opening 8 in chassis or panel 9. The bushing is shown as being of slightly lesser diameter than the diameter of the hole.'While the height of the bushing below the enlarged head 14, relative to the thickness of the panel, may vary, it is shown as being slightly in excess of two times the panel thickness, which is preferred. FIG. 1 shows the terminal before the pin has been driven home in the bushing. The annular barb has been driven slightly below the surface of the head and the lower end of the shank 16 is just above the lower end of bushing 11.

The assembly is in this condition when it leaves the manufacturer. It is placed in the opening 8 with flange 14 of the bushing in contact with the upper face of the chassis. The conductive pin is now driven downwardly a suflicient distance so that the upper portion of the knurled section enters that portion of the bushing enclosed between the upper and lower faces of the chassis. This is shown in FIGS. 2 and 3 as being accomplished in two steps, although it is, in fact, one continuous operation. In the first step in FIG. 2, the enlarged knurled section is beginning to pass into the area of the bushing enclosed by the walls of chassis hole 8, and shoulder 23 is still spaced from section 14. The continuing downward movement places knurled section 20 wholly within said enclosed area and shoulder 23 contacts the top of the bushing flange 14 which acts as a stop. The bushing material displaced from the hole flows below the panel and expands laterally to form shoulder 22 while barb-like flange 18 retains this section against subsequent elongation. Since the bushing material and the pin in the FIG.

1 condition has almost completely filled the chassis hole, the material must move and be displaced during transposition to the FIG. 3 position and the only place it can move is downwardly which increases the diameter and forms a shoulder 22. Pushing the larger diameter annular barb into the bore in the bushing tends to excessively elongate the bushing and for that reason the lower end of the bushing is supported.

Various tools can be used in this operation and one tool set up is shown as including an upper insertion tool 26 having a driver 28 in a sleeve 29 which has a bore 30 to receive the upper bifurcated section 24 of the pin. The tool assembly also includes a back-up tool 34, mounted in fixed relation to the lower face of the chassis and having a central opening 36 to receive the lower shank portion of pin 16. The opening has a counterbore 37 formed by a shoulder 38 and this counterbore is of such length as to provide a slight clearance of the order of about .005 inch between the shoulder and the lower end of the bushing in starting position. This shoulder is considered as the anvil.

When the driver moves downwardly to the position of FIG. 2 and the lower end of the bushing is supported by the anvil, the barb-like flange 18 moves downwardly in bore 12 almost to the lower end. During this downward movement, the tendency of the bushing to elongate is resisted by anvil 38 and when the tools are removed the lower end of the bushing has the bulbous configuration shown at 40, of larger diameter than hole 8, thus forming the shoulder 22 resisting withdrawal of the completed assembly. The flat annular ledge 19 retains the bushing in this condition. The enlarged diameter of the bushing results from the displacement of the material forming the bushing.

The foregoing structure is essentially a feed-through assembly and if a standoff assembly is required it is only necesary to shorten the pin.

A modified method and tool assembly is shown in FIGS. 4, and 6. The upper end of a spring loaded sleeve 44 is in constant contact with chassis 9. This sleeve has an enlarged section 46 forming an internal shoulder 48 against which a spring 49 acts. A fixed anvil 50 has a central bore 51 to receive the shank 16 of the pin 10. The lower end of the spring rests against collar 52 fixed at 54 on anvil 50.

The insertion tool 26 with its sleeve 29 and driver 28 is the same as before. Downward movement of the driver moves the pin down, which force is transmitted to the chassis, moving it downwardly against the sleeve 44, compressing the spring. The bushing has bottomed against the anvil in FIG. 5 and the conductive pin has moved downwardly through bushing bore 12. In FIG. 5, pin is completely seated. Further downward movement of the driver drives the annular flange to a position near the lower end of the bushing and this movement is accompanied by further downward travel of the sleeve 44 and chassis 9, causing the lower end of the bushing to be compressed against the fixed anvil and increase the diameter and thus from shoulder 22. In other words, movement of the parts from the FIG. 5 to the FIG. 6 position would tend to elongate the bushing but is prevented from doing so by the seat at the top of anvil 50 as the latter moves upwardly and performs a sort of riveting action and causes the bulge.

FIG. 1 shows a slight gap between the lower end of bushing 11 and the anvil 38, but in some cases, depending on tolerances, the bushing may touch the anvil in the first instance.

The principal difference in the method resides in the fact that in the first method, the bushing is firmly supported by the anvil from the time the driver starts to drive the pin from the position of FIG. 1 whereas in the second method the transposition of the parts from FIG. 5 to FIG. 6, the insulator, chassis and spring loaded sleeve have moved toward the anvil tool and this moves the sleeve 4446 downwardly compressing the spring 49 and also the bushing 11. In other words, as the pin is driven downwardly from the position of FIG. 5 towards the position of FIG. 6, the bushing may tend to elongate and at a certain point the spring loaded anvil 50 takes over and, in effect, pushes it 'back. It will be noted that by the time .the parts have reached this position of FIG. 6, the lower end of the shank 16 has moved further downwardly as has the barb-like annular flange 18. The insulator, supported on the anvil 50, has assumed a more spherical configuration and a shoulder 18 is formed at the upper end of the projecting part, thus preventing removal of the insulator.

It may be theorized that the insulating material displaced by the advancing conductive pin tends to cold flow axially which would normally increase the length of the insulator. This growth in length is restricted by placement of the fixed anvil in such a position that the cold flow is controlled or directed by expanding the insulator circumferentially rather than permitting the axial growth.

While there have been described herein what are at present considered preferred embodiments of the invention, it will be obvious to those skilled in the art that many modifications and changes may be made therein without departing from the essence of the invention.

What we claim is:

1. A two piece terminal assembly mounted in secured relation in a hole within a panel or the like, said assembly comprising a bushing having such a diameter as to move freely into said hole before installation, said bushing being formed of resilient, deformable insulating material and provided with a bore therethrough and a flat head at its upper end for limiting downward travel of the bushing into the hole, a conductive pin positioned within said bore and having a shank section and an enlarged non-smooth section above the shank section, a tapered portion between the shank section and the nonsmooth section, a fiat shoulder above the latter which contacts the flat head and forms a stop limiting downward movement of the pin, and a barb-like annular flange with a flat upper surface below the enlarged section which is positioned below and in spaced relation to the lower'surface of the panel while the enlarged section is positioned within the area of the bushing enclosed by the panel walls, and the portion of the bushing which has been displaced by the enlarged section as flowed downwardly and laterally into the area below said lower wall and said enlarged section has caused said portion to increase in diameter and form a shoulder at its upper end, restraining movement of the assembly out of the panel opening, the distance between the lower end of the bushing and said lower wall, in the finished assembly, being no greater than said distance when the bushing was intially inserted in the hole by virtue of said lower end being supported by said barb-like flange against substantial elongation during downward movement of the pin.

2. The assembly of claim 1 wherein the conductive pin is of such length as to form a stand-01f element.

3. The assembly of claim 1 wherein the conductive pin is of such length as to form a feed-through element.

4. The method of securing a deformable, insulating bushing with a flat head and with a conductive pin in the bushing, the pin being provided with an enlarged section near its upper end and an enlarged barb-like flange with a flat upper surface below said enlarged section, within an opening in a panel, which consists in driving the pin downwardly, while the head of the bushing is in contact with the upper face of the panel, and at the same time supporting the lower end of the bushing against elongation, continuing the downward driving movement until the barb-like flange has moved downwardly to a position below the panel andthe enlarged pin section has moved into the area between the faces of the panel, thus causing the bushing material to flow from said area into elongation.

References Cited UNITED STATES PATENTS Corey 174-153 Oxley 174-153 Abrams 174l66.1 X Maximoff et al. 174 -153 Just et al 174-153 X 6 3,095,470 6/1963 Dozier 174-1661 X 3,339,014 8/1967 Oxley 174-153 FOREIGN PATENTS 827,984 2/ 1960 Great Britain. 5 918,369 2/ 1963 Great Britain. 921,284 3/1963 Great Britain. 1,015,677 l/1966 Great Britain.

LARAMIE E. ASKIN, Primary Examiner 10 U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,504 ,107 March 31 1970 James Iantorno et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 47, "by the enlarged section as" should read by the enlarged section has Signed and sealed this 8th day of December 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, I r.

Commissioner of Patents Attesting Officer 

